Micro/nano structures induced by femtosecond laser to enhance light extraction of GaN-based LEDs

Tien-Li Chang, Zhao Chi Chen, Yeeu Chang Lee

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Surface texturing has been widely adopted to enhance the light extraction efficiency of light-emitting diodes (LEDs), and chemical etching is a technique commonly used to produce surface texturing. This study employed femtosecond lasers to apply ITO films directly onto the surface of LEDs to generate periodic micro/nanostructures and roughen the surface without contact or chemical substances. As a result, photons emitted in the active region escape into the free space, due to the scattering effect produced by texturing. This study discovered that light-emitting efficiency increases with surface roughness, and achieved an improvement of 18%. Caution regarding laser fluence was required during laser processing to avoid damaging the LED beneath the ITO film, which could detract from the electrical characteristics.

Original languageEnglish
Pages (from-to)15997-16002
Number of pages6
JournalOptics Express
Volume20
Issue number14
DOIs
Publication statusPublished - 2012 Jul 2

Fingerprint

light emitting diodes
ITO (semiconductors)
lasers
escape
surface roughness
fluence
etching
photons
scattering

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Micro/nano structures induced by femtosecond laser to enhance light extraction of GaN-based LEDs. / Chang, Tien-Li; Chen, Zhao Chi; Lee, Yeeu Chang.

In: Optics Express, Vol. 20, No. 14, 02.07.2012, p. 15997-16002.

Research output: Contribution to journalArticle

Chang, Tien-Li ; Chen, Zhao Chi ; Lee, Yeeu Chang. / Micro/nano structures induced by femtosecond laser to enhance light extraction of GaN-based LEDs. In: Optics Express. 2012 ; Vol. 20, No. 14. pp. 15997-16002.
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